Disk recording and reproduction devices are widely used to perform recording or reproduction by utilizing an optical pickup while rotating a disk recording medium. In this technology of the prior art, an optical disk constituting the disk recording medium is accessed by an optical pickup by rotating the optical disk on a turntable and moving the optical pickup along the radius direction of the optical disk, and the specified recording or reproduction is performed.
The laser light wavelength of the optical pickup varies according to the optical disk format. In the case of a CD (compact disk), for example, laser light of 780 nm (nanometers) wavelength is used. However, a DVD uses laser light of 650 nm wavelength. A so-called DVR capable of writing in a high density recording format utilizes laser light of 405 nm wavelength.
Using an optical pickup capable of emitting laser light at wavelengths suitable for all formats allows compatible use of all the above mentioned optical disk types by a single optical pickup.
Though installing two lenses and their respective laser emitters in a single pickup to actually use both DVR and DVD/CD was possible, an optical pickup of the prior art configured this way had the problem that the size was too large and adjustment was complicated.
Two types of optical disks are used. One type is a bare disk not utilizing a cartridge. The other type is an optical disk stored inside a cartridge. The bare disk must be placed on a turntable and clamped in place by a clamping means. Though differing depending on the format, cartridge type optical disks usually have a clamping means inside the cartridge and do not require a clamping means in the recording and reproduction apparatus itself. A disk recording and reproduction apparatus configured to use compatibly both cartridge type optical disks and bare disks therefore had the problem that a means was required to retract a clamping mechanism used especially when a cartridge type optical disk was inserted.
In view of the above-described problems, the present invention therefore has the object of providing a disk recording and reproduction apparatus capable of using multiple disk recording media that were impossible to be recorded or reproduced by a single pickup. A further object is to provide a disk recording and reproduction apparatus capable of retracting the clamping mechanism during loading of a cartridge type disk recording medium when a cartridge type disk recording medium or a bare disk type recording medium is selectively installed.